16 files changed, 407 insertions, 438 deletions

diff --git a/fpdfsdk/include/pdfwindow/PWL_Button.h b/fpdfsdk/include/pdfwindow/PWL_Button.h
index 363556762f..28a026c3bf 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Button.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Button.h
@@ -12,12 +12,13 @@
 class CPWL_Button : public CPWL_Wnd {
  public:
   CPWL_Button();
-  virtual ~CPWL_Button();
+  ~CPWL_Button() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 
  protected:
   FX_BOOL m_bMouseDown;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Caret.h b/fpdfsdk/include/pdfwindow/PWL_Caret.h
index 7e61eeb66e..0fe4e89c2e 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Caret.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Caret.h
@@ -21,15 +21,17 @@ struct PWL_CARET_INFO {
 class CPWL_Caret : public CPWL_Wnd {
  public:
   CPWL_Caret();
-  virtual ~CPWL_Caret();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void InvalidateRect(CPDF_Rect* pRect = NULL);
-  virtual void SetVisible(FX_BOOL bVisible) {}
-  virtual void TimerProc();
+  ~CPWL_Caret() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void InvalidateRect(CPDF_Rect* pRect = NULL) override;
+  void SetVisible(FX_BOOL bVisible) override {}
+  void TimerProc() override;
+
   void SetCaret(FX_BOOL bVisible,
                 const CPDF_Point& ptHead,
                 const CPDF_Point& ptFoot);
diff --git a/fpdfsdk/include/pdfwindow/PWL_ComboBox.h b/fpdfsdk/include/pdfwindow/PWL_ComboBox.h
index 98ae7ca986..e29752326c 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ComboBox.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ComboBox.h
@@ -13,17 +13,17 @@
 
 class CPWL_CBEdit : public CPWL_Edit {
  public:
-  CPWL_CBEdit(){};
-  virtual ~CPWL_CBEdit(){};
+  CPWL_CBEdit() {}
+  ~CPWL_CBEdit() override {}
 };
 
 class CPWL_CBListBox : public CPWL_ListBox {
  public:
-  CPWL_CBListBox(){};
-  virtual ~CPWL_CBListBox(){};
+  CPWL_CBListBox() {}
+  ~CPWL_CBListBox() override {}
 
- public:
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  // CPWL_ListBox
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 
   FX_BOOL OnKeyDownWithExit(FX_WORD nChar, FX_BOOL& bExit, FX_DWORD nFlag);
   FX_BOOL OnCharWithExit(FX_WORD nChar, FX_BOOL& bExit, FX_DWORD nFlag);
@@ -33,46 +33,40 @@ class CPWL_CBListBox : public CPWL_ListBox {
 
 class CPWL_CBButton : public CPWL_Wnd {
  public:
-  CPWL_CBButton(){};
-  virtual ~CPWL_CBButton(){};
-
- public:
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  CPWL_CBButton() {}
+  ~CPWL_CBButton() override {}
+
+  // CPWL_Wnd
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 };
 
 class CPWL_ComboBox : public CPWL_Wnd {
  public:
   CPWL_ComboBox();
-  operator CPWL_Edit*() { return m_pEdit; }
-
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
-
-  virtual CPDF_Rect GetFocusRect() const;
+  ~CPWL_ComboBox() {}
 
-  virtual void SetFocus();
-  virtual void KillFocus();
+  operator CPWL_Edit*() { return m_pEdit; }
 
-  FX_BOOL IsModified() const;
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  CPDF_Rect GetFocusRect() const override;
+  void SetFocus() override;
+  void KillFocus() override;
+  FX_BOOL IsModified() const override;
 
- public:
   void SetFillerNotify(IPWL_Filler_Notify* pNotify);
 
   CFX_WideString GetText() const;
@@ -90,28 +84,23 @@ class CPWL_ComboBox : public CPWL_Wnd {
 
   void SetSelectText();
 
+  void AttachFFLData(void* pData) { m_pFormFiller = pData; }
+
  private:
   void CreateEdit(const PWL_CREATEPARAM& cp);
   void CreateButton(const PWL_CREATEPARAM& cp);
   void CreateListBox(const PWL_CREATEPARAM& cp);
-
   void SetPopup(FX_BOOL bPopup);
 
- private:
   CPWL_CBEdit* m_pEdit;
   CPWL_CBButton* m_pButton;
   CPWL_CBListBox* m_pList;
-
   FX_BOOL m_bPopup;
   CPDF_Rect m_rcOldWindow;
   int32_t m_nPopupWhere;
   int32_t m_nSelectItem;
   IPWL_Filler_Notify* m_pFillerNotify;
 
- public:
-  void AttachFFLData(void* pData) { m_pFormFiller = pData; }
-
- private:
   void* m_pFormFiller;
 };
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_Edit.h b/fpdfsdk/include/pdfwindow/PWL_Edit.h
index 281bd268f4..11249a3193 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Edit.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Edit.h
@@ -44,32 +44,29 @@ class IPWL_Filler_Notify {
 class CPWL_Edit : public CPWL_EditCtrl, public IFX_Edit_OprNotify {
  public:
   CPWL_Edit();
-  virtual ~CPWL_Edit();
+  ~CPWL_Edit() override;
+
+  // CPWL_EditCtrl
+  CFX_ByteString GetClassName() const override;
+  void OnDestroy() override;
+  void OnCreated() override;
+  void RePosChildWnd() override;
+  CPDF_Rect GetClientRect() const override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDblClk(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  CPDF_Rect GetFocusRect() const override;
+  void OnSetFocus() override;
+  void OnKillFocus() override;
 
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnDestroy();
-  virtual void OnCreated();
-  virtual void RePosChildWnd();
-  virtual CPDF_Rect GetClientRect() const;
-
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonDblClk(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-
-  virtual CPDF_Rect GetFocusRect() const;
-
- public:
   void SetAlignFormatH(PWL_EDIT_ALIGNFORMAT_H nFormat = PEAH_LEFT,
                        FX_BOOL bPaint = TRUE);  // 0:left 1:right 2:middle
   void SetAlignFormatV(PWL_EDIT_ALIGNFORMAT_V nFormat = PEAV_TOP,
@@ -119,25 +116,22 @@ class CPWL_Edit : public CPWL_EditCtrl, public IFX_Edit_OprNotify {
                            const CPDF_Point& ptOffset);
 
  protected:
-  virtual void OnSetFocus();
-  virtual void OnKillFocus();
-
- protected:
-  virtual void OnInsertWord(const CPVT_WordPlace& place,
-                            const CPVT_WordPlace& oldplace);
-  virtual void OnInsertReturn(const CPVT_WordPlace& place,
-                              const CPVT_WordPlace& oldplace);
-  virtual void OnBackSpace(const CPVT_WordPlace& place,
-                           const CPVT_WordPlace& oldplace);
-  virtual void OnDelete(const CPVT_WordPlace& place,
-                        const CPVT_WordPlace& oldplace);
-  virtual void OnClear(const CPVT_WordPlace& place,
-                       const CPVT_WordPlace& oldplace);
-  virtual void OnSetText(const CPVT_WordPlace& place,
-                         const CPVT_WordPlace& oldplace);
-  virtual void OnInsertText(const CPVT_WordPlace& place,
-                            const CPVT_WordPlace& oldplace);
-  virtual void OnAddUndo(IFX_Edit_UndoItem* pUndoItem);
+  // IFX_Edit_OprNotify
+  void OnInsertWord(const CPVT_WordPlace& place,
+                    const CPVT_WordPlace& oldplace) override;
+  void OnInsertReturn(const CPVT_WordPlace& place,
+                      const CPVT_WordPlace& oldplace) override;
+  void OnBackSpace(const CPVT_WordPlace& place,
+                   const CPVT_WordPlace& oldplace) override;
+  void OnDelete(const CPVT_WordPlace& place,
+                const CPVT_WordPlace& oldplace) override;
+  void OnClear(const CPVT_WordPlace& place,
+               const CPVT_WordPlace& oldplace) override;
+  void OnSetText(const CPVT_WordPlace& place,
+                 const CPVT_WordPlace& oldplace) override;
+  void OnInsertText(const CPVT_WordPlace& place,
+                    const CPVT_WordPlace& oldplace) override;
+  void OnAddUndo(IFX_Edit_UndoItem* pUndoItem) override;
 
  private:
   CPVT_WordRange GetSelectWordRange() const;
diff --git a/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h b/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h
index 784ec61140..bd241a3a48 100644
--- a/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h
+++ b/fpdfsdk/include/pdfwindow/PWL_EditCtrl.h
@@ -57,37 +57,10 @@ class CPWL_EditCtrl : public CPWL_Wnd, public IFX_Edit_Notify {
 
  public:
   CPWL_EditCtrl();
-  virtual ~CPWL_EditCtrl();
-
- public:
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual void OnCreated();
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
-  virtual void SetFontSize(FX_FLOAT fFontSize);
-  virtual FX_FLOAT GetFontSize() const;
-
- public:
-  virtual void SetText(const FX_WCHAR* csText);
-
-  virtual void CopyText();
-  virtual void PasteText();
-  virtual void CutText();
+  ~CPWL_EditCtrl() override;
 
   CPDF_Rect GetContentRect() const;
   void GetCaretPos(int32_t& x, int32_t& y) const;
-  FX_BOOL IsModified() const;
 
   CFX_WideString GetText() const;
   void SetSel(int32_t nStartChar, int32_t nEndChar);
@@ -127,20 +100,64 @@ class CPWL_EditCtrl : public CPWL_Wnd, public IFX_Edit_Notify {
 
   void SetReadyToInput();
 
- protected:
-  virtual void ShowVScrollBar(FX_BOOL bShow);
+  // CPWL_Wnd
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  void OnCreated() override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  void SetFontSize(FX_FLOAT fFontSize) override;
+  FX_FLOAT GetFontSize() const override;
+  void SetCursor() override;
+  FX_BOOL IsModified() const override;
 
-  virtual void InsertWord(FX_WORD word, int32_t nCharset);
-  virtual void InsertReturn();
-  virtual void InsertText(const FX_WCHAR* csText);
+ protected:
+  // IFX_Edit_Notify
+  void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
+                         FX_FLOAT fPlateMax,
+                         FX_FLOAT fContentMin,
+                         FX_FLOAT fContentMax,
+                         FX_FLOAT fSmallStep,
+                         FX_FLOAT fBigStep) override {}
+  void IOnSetScrollInfoY(FX_FLOAT fPlateMin,
+                         FX_FLOAT fPlateMax,
+                         FX_FLOAT fContentMin,
+                         FX_FLOAT fContentMax,
+                         FX_FLOAT fSmallStep,
+                         FX_FLOAT fBigStep) override;
+  void IOnSetScrollPosX(FX_FLOAT fx) override {}
+  void IOnSetScrollPosY(FX_FLOAT fy) override;
+  void IOnSetCaret(FX_BOOL bVisible,
+                   const CPDF_Point& ptHead,
+                   const CPDF_Point& ptFoot,
+                   const CPVT_WordPlace& place) override;
+  void IOnCaretChange(const CPVT_SecProps& secProps,
+                      const CPVT_WordProps& wordProps) override;
+  void IOnContentChange(const CPDF_Rect& rcContent) override;
+  void IOnInvalidateRect(CPDF_Rect* pRect) override;
+
+  void InsertText(const FX_WCHAR* csText);
+  void SetText(const FX_WCHAR* csText);
+  void CopyText();
+  void PasteText();
+  void CutText();
+  void ShowVScrollBar(FX_BOOL bShow);
+  void InsertWord(FX_WORD word, int32_t nCharset);
+  void InsertReturn();
 
-  virtual void SetCursor();
   FX_BOOL IsWndHorV();
 
   void Delete();
   void Backspace();
 
- protected:
   void GetCaretInfo(CPDF_Point& ptHead, CPDF_Point& ptFoot) const;
   void SetCaret(FX_BOOL bVisible,
                 const CPDF_Point& ptHead,
@@ -148,30 +165,6 @@ class CPWL_EditCtrl : public CPWL_Wnd, public IFX_Edit_Notify {
 
   void SetEditCaret(FX_BOOL bVisible);
 
- protected:
-  virtual void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
-                                 FX_FLOAT fPlateMax,
-                                 FX_FLOAT fContentMin,
-                                 FX_FLOAT fContentMax,
-                                 FX_FLOAT fSmallStep,
-                                 FX_FLOAT fBigStep) {}
-  virtual void IOnSetScrollInfoY(FX_FLOAT fPlateMin,
-                                 FX_FLOAT fPlateMax,
-                                 FX_FLOAT fContentMin,
-                                 FX_FLOAT fContentMax,
-                                 FX_FLOAT fSmallStep,
-                                 FX_FLOAT fBigStep);
-  virtual void IOnSetScrollPosX(FX_FLOAT fx) {}
-  virtual void IOnSetScrollPosY(FX_FLOAT fy);
-  virtual void IOnSetCaret(FX_BOOL bVisible,
-                           const CPDF_Point& ptHead,
-                           const CPDF_Point& ptFoot,
-                           const CPVT_WordPlace& place);
-  virtual void IOnCaretChange(const CPVT_SecProps& secProps,
-                              const CPVT_WordProps& wordProps);
-  virtual void IOnContentChange(const CPDF_Rect& rcContent);
-  virtual void IOnInvalidateRect(CPDF_Rect* pRect);
-
  private:
   void CreateEditCaret(const PWL_CREATEPARAM& cp);
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_FontMap.h b/fpdfsdk/include/pdfwindow/PWL_FontMap.h
index 0f5124ca02..f91d7e823f 100644
--- a/fpdfsdk/include/pdfwindow/PWL_FontMap.h
+++ b/fpdfsdk/include/pdfwindow/PWL_FontMap.h
@@ -51,24 +51,20 @@ struct CPWL_FontMap_Native {
 class CPWL_FontMap : public IFX_Edit_FontMap {
  public:
   CPWL_FontMap(IFX_SystemHandler* pSystemHandler);
-  virtual ~CPWL_FontMap();
+  ~CPWL_FontMap() override;
 
-  virtual CPDF_Font* GetPDFFont(int32_t nFontIndex);
-  virtual CFX_ByteString GetPDFFontAlias(int32_t nFontIndex);
-  virtual int32_t GetWordFontIndex(FX_WORD word,
-                                   int32_t nCharset,
-                                   int32_t nFontIndex);
-  virtual int32_t CharCodeFromUnicode(int32_t nFontIndex, FX_WORD word);
-  virtual int32_t CharSetFromUnicode(FX_WORD word, int32_t nOldCharset);
+  // IFX_Edit_FontMap
+  CPDF_Font* GetPDFFont(int32_t nFontIndex) override;
+  CFX_ByteString GetPDFFontAlias(int32_t nFontIndex) override;
+  int32_t GetWordFontIndex(FX_WORD word,
+                           int32_t nCharset,
+                           int32_t nFontIndex) override;
+  int32_t CharCodeFromUnicode(int32_t nFontIndex, FX_WORD word) override;
+  int32_t CharSetFromUnicode(FX_WORD word, int32_t nOldCharset) override;
 
- public:
-  virtual void Initial(const FX_CHAR* fontname = NULL);
   void SetSystemHandler(IFX_SystemHandler* pSystemHandler);
-
   int32_t GetFontMapCount() const;
   const CPWL_FontMap_Data* GetFontMapData(int32_t nIndex) const;
-
- public:
   static int32_t GetNativeCharset();
   CFX_ByteString GetNativeFontName(int32_t nCharset);
 
@@ -84,12 +80,12 @@ class CPWL_FontMap : public IFX_Edit_FontMap {
                            uint8_t nCharset);
 
  protected:
-  virtual CPDF_Font* FindFontSameCharset(CFX_ByteString& sFontAlias,
-                                         int32_t nCharset);
-  virtual void AddedFont(CPDF_Font* pFont, const CFX_ByteString& sFontAlias);
-  FX_BOOL KnowWord(int32_t nFontIndex, FX_WORD word);
+  void Initial(const FX_CHAR* fontname = NULL);
+  CPDF_Document* GetDocument();
+  CPDF_Font* FindFontSameCharset(CFX_ByteString& sFontAlias, int32_t nCharset);
+  void AddedFont(CPDF_Font* pFont, const CFX_ByteString& sFontAlias);
 
-  virtual CPDF_Document* GetDocument();
+  FX_BOOL KnowWord(int32_t nFontIndex, FX_WORD word);
 
   void Empty();
   int32_t GetFontIndex(const CFX_ByteString& sFontName,
@@ -128,7 +124,7 @@ class CPWL_DocFontMap : public CPWL_FontMap {
  public:
   CPWL_DocFontMap(IFX_SystemHandler* pSystemHandler,
                   CPDF_Document* pAttachedDoc);
-  virtual ~CPWL_DocFontMap();
+  ~CPWL_DocFontMap() override;
 
   virtual CPDF_Document* GetDocument();
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_Icon.h b/fpdfsdk/include/pdfwindow/PWL_Icon.h
index 7183f0245c..95157cad1f 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Icon.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Icon.h
@@ -13,7 +13,7 @@
 class CPWL_Image : public CPWL_Wnd {
  public:
   CPWL_Image();
-  virtual ~CPWL_Image();
+  ~CPWL_Image() override;
 
   virtual CFX_ByteString GetImageAppStream();
 
@@ -36,12 +36,13 @@ class CPWL_Image : public CPWL_Wnd {
 class CPWL_Icon : public CPWL_Image {
  public:
   CPWL_Icon();
-  virtual ~CPWL_Icon();
+  ~CPWL_Icon() override;
 
   virtual CPDF_IconFit* GetIconFit() { return m_pIconFit; };
 
-  virtual void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale);
-  virtual void GetImageOffset(FX_FLOAT& x, FX_FLOAT& y);
+  // CPWL_Image
+  void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale) override;
+  void GetImageOffset(FX_FLOAT& x, FX_FLOAT& y) override;
 
   int32_t GetScaleMethod();
   FX_BOOL IsProportionalScale();
diff --git a/fpdfsdk/include/pdfwindow/PWL_IconList.h b/fpdfsdk/include/pdfwindow/PWL_IconList.h
index 30a12dcd9b..9ffb5ee8f5 100644
--- a/fpdfsdk/include/pdfwindow/PWL_IconList.h
+++ b/fpdfsdk/include/pdfwindow/PWL_IconList.h
@@ -26,11 +26,7 @@ class IPWL_IconList_Notify {
 class CPWL_IconList_Item : public CPWL_Wnd {
  public:
   CPWL_IconList_Item();
-  virtual ~CPWL_IconList_Item();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
+  ~CPWL_IconList_Item() override;
 
   void SetSelect(FX_BOOL bSelected);
   FX_BOOL IsSelected() const;
@@ -41,12 +37,15 @@ class CPWL_IconList_Item : public CPWL_Wnd {
   CFX_WideString GetText() const;
 
  protected:
-  virtual FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual void OnEnabled();
-  virtual void OnDisabled();
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void OnEnabled() override;
+  void OnDisabled() override;
 
  private:
   int32_t m_nIconIndex;
@@ -59,7 +58,7 @@ class CPWL_IconList_Item : public CPWL_Wnd {
 class CPWL_IconList_Content : public CPWL_ListCtrl {
  public:
   CPWL_IconList_Content(int32_t nListCount);
-  virtual ~CPWL_IconList_Content();
+  ~CPWL_IconList_Content() override;
 
   void SetSelect(int32_t nIndex);
   int32_t GetSelect() const;
@@ -74,11 +73,12 @@ class CPWL_IconList_Content : public CPWL_ListCtrl {
   void ScrollToItem(int32_t nItemIndex);
 
  protected:
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
+  // CPWL_ListCtrl
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
 
  private:
   CPWL_IconList_Item* GetListItem(int32_t nItemIndex) const;
@@ -95,11 +95,7 @@ class CPWL_IconList_Content : public CPWL_ListCtrl {
 class CPWL_IconList : public CPWL_Wnd {
  public:
   CPWL_IconList(int32_t nListCount);
-  virtual ~CPWL_IconList();
-
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
+  ~CPWL_IconList() override;
 
   void SetSelect(int32_t nIndex);
   void SetTopItem(int32_t nIndex);
@@ -113,14 +109,17 @@ class CPWL_IconList : public CPWL_Wnd {
   CFX_WideString GetListString(int32_t nItemIndex) const;
 
  protected:
-  virtual void OnCreated();
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
+  // CPWL_Wnd
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  void OnCreated() override;
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
 
  private:
   CPWL_IconList_Content* m_pListContent;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Label.h b/fpdfsdk/include/pdfwindow/PWL_Label.h
index b6cb7f557c..0504bb3e0b 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Label.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Label.h
@@ -14,11 +14,7 @@ class IFX_Edit;
 class CPWL_Label : public CPWL_Wnd {
  public:
   CPWL_Label();
-  virtual ~CPWL_Label();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void SetFontSize(FX_FLOAT fFontSize);
-  virtual FX_FLOAT GetFontSize() const;
+  ~CPWL_Label() override;
 
   void SetText(const FX_WCHAR* csText);
   CFX_WideString GetText() const;
@@ -30,11 +26,15 @@ class CPWL_Label : public CPWL_Wnd {
   CFX_ByteString GetTextAppearanceStream(const CPDF_Point& ptOffset) const;
 
  protected:
-  virtual void OnCreated();
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void RePosChildWnd();
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void SetFontSize(FX_FLOAT fFontSize) override;
+  FX_FLOAT GetFontSize() const override;
+  void OnCreated() override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void RePosChildWnd() override;
 
  private:
   void SetParamByFlag();
diff --git a/fpdfsdk/include/pdfwindow/PWL_ListBox.h b/fpdfsdk/include/pdfwindow/PWL_ListBox.h
index b9372eff9c..942a568836 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ListBox.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ListBox.h
@@ -18,29 +18,31 @@ class IPWL_Filler_Notify;
 class CPWL_List_Notify : public IFX_List_Notify {
  public:
   CPWL_List_Notify(CPWL_ListBox* pList);
-  virtual ~CPWL_List_Notify();
+  ~CPWL_List_Notify() override;
 
+  // IFX_List_Notify
   void IOnSetScrollInfoX(FX_FLOAT fPlateMin,
                          FX_FLOAT fPlateMax,
                          FX_FLOAT fContentMin,
                          FX_FLOAT fContentMax,
                          FX_FLOAT fSmallStep,
-                         FX_FLOAT fBigStep) {}
+                         FX_FLOAT fBigStep) override {}
   void IOnSetScrollInfoY(FX_FLOAT fPlateMin,
                          FX_FLOAT fPlateMax,
                          FX_FLOAT fContentMin,
                          FX_FLOAT fContentMax,
                          FX_FLOAT fSmallStep,
-                         FX_FLOAT fBigStep);
-  void IOnSetScrollPosX(FX_FLOAT fx) {}
-  void IOnSetScrollPosY(FX_FLOAT fy);
+                         FX_FLOAT fBigStep) override;
+  void IOnSetScrollPosX(FX_FLOAT fx) override {}
+  void IOnSetScrollPosY(FX_FLOAT fy) override;
+  void IOnInvalidateRect(CPDF_Rect* pRect) override;
+
   void IOnSetCaret(FX_BOOL bVisible,
                    const CPDF_Point& ptHead,
                    const CPDF_Point& ptFoot,
                    const CPVT_WordPlace& place);
   void IOnCaretChange(const CPVT_SecProps& secProps,
                       const CPVT_WordProps& wordProps);
-  void IOnInvalidateRect(CPDF_Rect* pRect);
 
  private:
   CPWL_ListBox* m_pList;
@@ -49,34 +51,34 @@ class CPWL_List_Notify : public IFX_List_Notify {
 class CPWL_ListBox : public CPWL_Wnd {
  public:
   CPWL_ListBox();
-  virtual ~CPWL_ListBox();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreated();
-  virtual void OnDestroy();
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
-  virtual void KillFocus();
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-  virtual void RePosChildWnd();
+  ~CPWL_ListBox() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreated() override;
+  void OnDestroy() override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnKeyDown(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  void KillFocus() override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void RePosChildWnd() override;
+  CPDF_Rect GetFocusRect() const override;
+  void SetFontSize(FX_FLOAT fFontSize) override;
+  FX_FLOAT GetFontSize() const override;
+
   virtual CFX_WideString GetText() const;
-  virtual CPDF_Rect GetFocusRect() const;
-  virtual void SetFontSize(FX_FLOAT fFontSize);
-  virtual FX_FLOAT GetFontSize() const;
 
   void OnNotifySelChanged(FX_BOOL bKeyDown, FX_BOOL& bExit, FX_DWORD nFlag);
 
diff --git a/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h b/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h
index cd90692150..dbaffc5b58 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ListCtrl.h
@@ -12,7 +12,7 @@
 class CPWL_ListCtrl : public CPWL_Wnd {
  public:
   CPWL_ListCtrl();
-  virtual ~CPWL_ListCtrl();
+  ~CPWL_ListCtrl() override;
 
   void SetScrollPos(const CPDF_Point& point);
   CPDF_Point GetScrollPos() const;
@@ -30,9 +30,10 @@ class CPWL_ListCtrl : public CPWL_Wnd {
   CPDF_Rect OutToIn(const CPDF_Rect& rect) const;
 
  protected:
-  virtual void RePosChildWnd();
-  virtual void DrawChildAppearance(CFX_RenderDevice* pDevice,
-                                   CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void RePosChildWnd() override;
+  void DrawChildAppearance(CFX_RenderDevice* pDevice,
+                           CPDF_Matrix* pUser2Device) override;
 
  private:
   void ResetAll(FX_BOOL bMove, int32_t nStart);
diff --git a/fpdfsdk/include/pdfwindow/PWL_Note.h b/fpdfsdk/include/pdfwindow/PWL_Note.h
index 4f18fa20d0..b25d989ec7 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Note.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Note.h
@@ -82,14 +82,14 @@ class IPWL_NoteItem {
 class CPWL_Note_Icon : public CPWL_Wnd {
  public:
   CPWL_Note_Icon();
-  virtual ~CPWL_Note_Icon();
+  ~CPWL_Note_Icon() override;
 
   void SetIconType(int32_t nType);
 
- public:
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
 
  private:
   int32_t m_nType;
@@ -98,13 +98,14 @@ class CPWL_Note_Icon : public CPWL_Wnd {
 class CPWL_Note_CloseBox : public CPWL_Button {
  public:
   CPWL_Note_CloseBox();
-  virtual ~CPWL_Note_CloseBox();
+  ~CPWL_Note_CloseBox() override;
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
+  // CPWL_Button
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
 
  private:
   FX_BOOL m_bMouseDown;
@@ -113,43 +114,44 @@ class CPWL_Note_CloseBox : public CPWL_Button {
 class CPWL_Note_LBBox : public CPWL_Wnd {
  public:
   CPWL_Note_LBBox();
-  virtual ~CPWL_Note_LBBox();
+  ~CPWL_Note_LBBox() override;
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
 };
 
 class CPWL_Note_RBBox : public CPWL_Wnd {
  public:
   CPWL_Note_RBBox();
-  virtual ~CPWL_Note_RBBox();
+  ~CPWL_Note_RBBox() override;
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
 };
 
 class CPWL_Note_Edit : public CPWL_Edit {
  public:
   CPWL_Note_Edit();
-  virtual ~CPWL_Note_Edit();
+  ~CPWL_Note_Edit() override;
 
   void EnableNotify(FX_BOOL bEnable) { m_bEnableNotify = bEnable; }
-  virtual FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth);
-  FX_FLOAT GetItemLeftMargin();
-  FX_FLOAT GetItemRightMargin();
-
-  virtual void SetText(const FX_WCHAR* csText);
 
- protected:
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-  virtual void RePosChildWnd();
-  virtual void OnSetFocus();
-  virtual void OnKillFocus();
+  // CPWL_Edit
+  FX_FLOAT GetItemLeftMargin() override;
+  FX_FLOAT GetItemRightMargin() override;
+  FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth) override;
+  void SetText(const FX_WCHAR* csText) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void RePosChildWnd() override;
+  void OnSetFocus() override;
+  void OnKillFocus() override;
 
  private:
   FX_BOOL m_bEnableNotify;
@@ -162,17 +164,17 @@ class CPWL_Note_Edit : public CPWL_Edit {
 class CPWL_Note_Options : public CPWL_Wnd {
  public:
   CPWL_Note_Options();
-  virtual ~CPWL_Note_Options();
+  ~CPWL_Note_Options() override;
 
   CPDF_Rect GetContentRect() const;
-  virtual void SetTextColor(const CPWL_Color& color);
   void SetText(const CFX_WideString& sText);
 
- protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
+  // CPWL_Wnd
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void SetTextColor(const CPWL_Color& color) override;
 
  private:
   CPWL_Label* m_pText;
@@ -181,19 +183,11 @@ class CPWL_Note_Options : public CPWL_Wnd {
 class CPWL_Note_Contents : public CPWL_ListCtrl {
  public:
   CPWL_Note_Contents();
-  virtual ~CPWL_Note_Contents();
-
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
+  ~CPWL_Note_Contents() override;
 
   void SetEditFocus(FX_BOOL bLast);
   CPWL_Edit* GetEdit() const;
 
- public:
   void SetText(const CFX_WideString& sText);
   CFX_WideString GetText() const;
 
@@ -206,8 +200,14 @@ class CPWL_Note_Contents : public CPWL_ListCtrl {
   void EnableRead(FX_BOOL bEnabled);
   void EnableModify(FX_BOOL bEnabled);
 
- protected:
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
+  // CPWL_ListCtrl
+  CFX_ByteString GetClassName() const override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
 
  private:
   CPWL_Note_Edit* m_pEdit;
@@ -216,65 +216,60 @@ class CPWL_Note_Contents : public CPWL_ListCtrl {
 class CPWL_NoteItem : public CPWL_Wnd, public IPWL_NoteItem {
  public:
   CPWL_NoteItem();
-  virtual ~CPWL_NoteItem();
-
- public:
-  virtual void SetPrivateData(void* pData);
-  virtual void SetBkColor(const CPWL_Color& color);
-  virtual void SetSubjectName(const CFX_WideString& sName);
-  virtual void SetAuthorName(const CFX_WideString& sName);
-  virtual void SetDateTime(FX_SYSTEMTIME time);
-  virtual void SetContents(const CFX_WideString& sContents);
-
-  virtual IPWL_NoteItem* CreateSubItem();
-  virtual int32_t CountSubItems() const;
-  virtual IPWL_NoteItem* GetSubItems(int32_t index) const;
-  virtual void DeleteSubItem(IPWL_NoteItem* pNoteItem);
-  virtual void SetFocus() { SetNoteFocus(FALSE); }
-
-  virtual IPWL_NoteItem* GetParentItem() const;
-  virtual void* GetPrivateData() const;
-  virtual CFX_WideString GetAuthorName() const;
-  virtual CPWL_Color GetBkColor() const;
-  virtual CFX_WideString GetContents() const;
-  virtual FX_SYSTEMTIME GetDateTime() const;
-  virtual CFX_WideString GetSubjectName() const;
-  virtual FX_BOOL IsTopItem() const { return FALSE; }
-  virtual CPWL_Edit* GetEdit() const;
+  ~CPWL_NoteItem() override;
 
- public:
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual CFX_ByteString GetClassName() const;
   virtual IPWL_NoteItem* GetHitNoteItem(const CPDF_Point& point);
   virtual IPWL_NoteItem* GetFocusedNoteItem() const;
 
+  virtual FX_BOOL IsTopItem() const { return FALSE; }
+
   virtual void ResetSubjectName(int32_t nItemIndex);
   void EnableRead(FX_BOOL bEnabled);
   void EnableModify(FX_BOOL bEnabled);
 
- protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
+  void OnContentsValidate();
+  void OnCreateNoteItem();
 
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
+  // IPWL_NoteItem
+  void SetPrivateData(void* pData) override;
+  void SetBkColor(const CPWL_Color& color) override;
+  void SetSubjectName(const CFX_WideString& sName) override;
+  void SetAuthorName(const CFX_WideString& sName) override;
+  void SetDateTime(FX_SYSTEMTIME time) override;
+  void SetContents(const CFX_WideString& sContents) override;
+  IPWL_NoteItem* CreateSubItem() override;
+  int32_t CountSubItems() const override;
+  IPWL_NoteItem* GetSubItems(int32_t index) const override;
+  void DeleteSubItem(IPWL_NoteItem* pNoteItem) override;
+  void SetFocus() override { SetNoteFocus(FALSE); }
+  IPWL_NoteItem* GetParentItem() const override;
+  void* GetPrivateData() const override;
+  CFX_WideString GetAuthorName() const override;
+  CPWL_Color GetBkColor() const override;
+  CFX_WideString GetContents() const override;
+  FX_SYSTEMTIME GetDateTime() const override;
+  CFX_WideString GetSubjectName() const override;
+  CPWL_Edit* GetEdit() const override;
+
+ protected:
+  // CPWL_Wnd
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  CFX_ByteString GetClassName() const override;
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth) override;
+  FX_FLOAT GetItemLeftMargin() override;
+  FX_FLOAT GetItemRightMargin() override;
 
- public:
-  virtual FX_FLOAT GetItemHeight(FX_FLOAT fLimitWidth);
-  virtual FX_FLOAT GetItemLeftMargin();
-  virtual FX_FLOAT GetItemRightMargin();
   CPWL_NoteItem* CreateNoteItem();
   CPWL_NoteItem* GetParentNoteItem() const;
 
   void SetNoteFocus(FX_BOOL bLast);
-  void OnContentsValidate();
-
-  void OnCreateNoteItem();
-
- protected:
   void PopupNoteItemMenu(const CPDF_Point& point);
 
   virtual const CPWL_Note* GetNote() const;
@@ -300,19 +295,8 @@ class CPWL_Note : public CPWL_NoteItem {
   CPWL_Note(IPopup_Note* pPopupNote,
             IPWL_NoteNotify* pNoteNotify,
             IPWL_NoteHandler* pNoteHandler);
-  virtual ~CPWL_Note();
+  ~CPWL_Note() override;
 
- public:
-  virtual void SetSubjectName(const CFX_WideString& sName);
-  virtual void SetAuthorName(const CFX_WideString& sName);
-  virtual CFX_WideString GetAuthorName() const;
-  virtual void SetBkColor(const CPWL_Color& color);
-  virtual void ResetSubjectName(int32_t nItemIndex) {}
-  virtual FX_BOOL IsTopItem() const { return TRUE; }
-  virtual const CPWL_Note* GetNote() const;
-  virtual IPWL_NoteNotify* GetNoteNotify() const;
-
- public:
   IPWL_NoteItem* Reply();
   void EnableNotify(FX_BOOL bEnabled);
   void SetIconType(int32_t nType);
@@ -329,22 +313,28 @@ class CPWL_Note : public CPWL_NoteItem {
   CPDF_Rect GetCaptionRect() const { return m_rcCaption; }
   IPopup_Note* GetPopupNote() const { return m_pPopupNote; }
 
- public:
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseWheel(short zDelta,
-                               const CPDF_Point& point,
-                               FX_DWORD nFlag);
+  // CPWL_NoteItem
+  void SetSubjectName(const CFX_WideString& sName) override;
+  void SetAuthorName(const CFX_WideString& sName) override;
+  CFX_WideString GetAuthorName() const override;
+  void SetBkColor(const CPWL_Color& color) override;
+  void ResetSubjectName(int32_t nItemIndex) override {}
+  FX_BOOL IsTopItem() const override { return TRUE; }
+  const CPWL_Note* GetNote() const override;
+  IPWL_NoteNotify* GetNoteNotify() const override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnRButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseWheel(short zDelta,
+                       const CPDF_Point& point,
+                       FX_DWORD nFlag) override;
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
 
  protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
   FX_BOOL ResetScrollBar();
   void RePosNoteChildren();
   FX_BOOL ScrollBarShouldVisible();
diff --git a/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h b/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h
index a149a01416..ec1b78ed5e 100644
--- a/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h
+++ b/fpdfsdk/include/pdfwindow/PWL_ScrollBar.h
@@ -35,17 +35,17 @@ class CPWL_SBButton : public CPWL_Wnd {
  public:
   CPWL_SBButton(PWL_SCROLLBAR_TYPE eScrollBarType,
                 PWL_SBBUTTON_TYPE eButtonType);
-  virtual ~CPWL_SBButton();
-
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag);
+  ~CPWL_SBButton() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnMouseMove(const CPDF_Point& point, FX_DWORD nFlag) override;
 
  protected:
   PWL_SCROLLBAR_TYPE m_eScrollBarType;
@@ -92,24 +92,23 @@ struct PWL_SCROLL_PRIVATEDATA {
 class CPWL_ScrollBar : public CPWL_Wnd {
  public:
   CPWL_ScrollBar(PWL_SCROLLBAR_TYPE sbType = SBT_HSCROLL);
-  virtual ~CPWL_ScrollBar();
-
- public:
-  virtual CFX_ByteString GetClassName() const;
-  virtual void OnCreate(PWL_CREATEPARAM& cp);
-  virtual void RePosChildWnd();
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-
-  virtual FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual void OnNotify(CPWL_Wnd* pWnd,
-                        FX_DWORD msg,
-                        intptr_t wParam = 0,
-                        intptr_t lParam = 0);
-
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
+  ~CPWL_ScrollBar() override;
+
+  // CPWL_Wnd
+  CFX_ByteString GetClassName() const override;
+  void OnCreate(PWL_CREATEPARAM& cp) override;
+  void RePosChildWnd() override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  FX_BOOL OnLButtonDown(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  void OnNotify(CPWL_Wnd* pWnd,
+                FX_DWORD msg,
+                intptr_t wParam = 0,
+                intptr_t lParam = 0) override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void TimerProc() override;
 
   FX_FLOAT GetScrollBarWidth() const;
   PWL_SCROLLBAR_TYPE GetScrollBarType() const { return m_sbType; };
@@ -142,9 +141,6 @@ class CPWL_ScrollBar : public CPWL_Wnd {
   FX_FLOAT TrueToFace(FX_FLOAT);
   FX_FLOAT FaceToTrue(FX_FLOAT);
 
-  virtual void TimerProc();
-
- private:
   PWL_SCROLLBAR_TYPE m_sbType;
   PWL_SCROLL_INFO m_OriginInfo;
   CPWL_SBButton* m_pMinButton;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Signature.h b/fpdfsdk/include/pdfwindow/PWL_Signature.h
index c48d4e9708..009dd87592 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Signature.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Signature.h
@@ -16,17 +16,17 @@ class CPWL_Label;
 class CPWL_Signature_Image : public CPWL_Image {
  public:
   CPWL_Signature_Image();
-  virtual ~CPWL_Signature_Image();
+  ~CPWL_Signature_Image() override;
 
   void SetImage(CFX_DIBSource* pImage);
   CFX_DIBSource* GetImage();
 
  protected:
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
-
-  virtual void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale);
+  // CPWL_Image
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
+  void GetScale(FX_FLOAT& fHScale, FX_FLOAT& fVScale) override;
 
  private:
   CFX_DIBSource* m_pImage;
@@ -35,7 +35,7 @@ class CPWL_Signature_Image : public CPWL_Image {
 class CPWL_Signature : public CPWL_Wnd {
  public:
   CPWL_Signature();
-  virtual ~CPWL_Signature();
+  ~CPWL_Signature() override;
 
   void SetText(const FX_WCHAR* sText);
   void SetDescription(const FX_WCHAR* string);
@@ -47,12 +47,12 @@ class CPWL_Signature : public CPWL_Wnd {
   void SetFoxitFlag(FX_BOOL bFlagExist);
 
  protected:
-  virtual void RePosChildWnd();
-  virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
-
-  virtual void DrawThisAppearance(CFX_RenderDevice* pDevice,
-                                  CPDF_Matrix* pUser2Device);
-  virtual void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream);
+  // CPWL_Wnd
+  void RePosChildWnd() override;
+  void CreateChildWnd(const PWL_CREATEPARAM& cp) override;
+  void DrawThisAppearance(CFX_RenderDevice* pDevice,
+                          CPDF_Matrix* pUser2Device) override;
+  void GetThisAppearanceStream(CFX_ByteTextBuf& sAppStream) override;
 
  private:
   CPWL_Label* m_pText;
diff --git a/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h b/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h
index 8cfe819a67..a62d18d257 100644
--- a/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h
+++ b/fpdfsdk/include/pdfwindow/PWL_SpecialButton.h
@@ -12,20 +12,22 @@
 class CPWL_PushButton : public CPWL_Button {
  public:
   CPWL_PushButton();
-  virtual ~CPWL_PushButton();
+  ~CPWL_PushButton() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual CPDF_Rect GetFocusRect() const;
+  // CPWL_Button
+  CFX_ByteString GetClassName() const override;
+  CPDF_Rect GetFocusRect() const override;
 };
 
 class CPWL_CheckBox : public CPWL_Button {
  public:
   CPWL_CheckBox();
-  virtual ~CPWL_CheckBox();
+  ~CPWL_CheckBox() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
+  // CPWL_Button
+  CFX_ByteString GetClassName() const override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
 
   void SetCheck(FX_BOOL bCheck);
   FX_BOOL IsChecked() const;
@@ -37,11 +39,12 @@ class CPWL_CheckBox : public CPWL_Button {
 class CPWL_RadioButton : public CPWL_Button {
  public:
   CPWL_RadioButton();
-  virtual ~CPWL_RadioButton();
+  ~CPWL_RadioButton() override;
 
-  virtual CFX_ByteString GetClassName() const;
-  virtual FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag);
-  virtual FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag);
+  // CPWL_Button
+  CFX_ByteString GetClassName() const override;
+  FX_BOOL OnLButtonUp(const CPDF_Point& point, FX_DWORD nFlag) override;
+  FX_BOOL OnChar(FX_WORD nChar, FX_DWORD nFlag) override;
 
   void SetCheck(FX_BOOL bCheck);
   FX_BOOL IsChecked() const;
diff --git a/fpdfsdk/include/pdfwindow/PWL_Wnd.h b/fpdfsdk/include/pdfwindow/PWL_Wnd.h
index e66c15e5e7..37af083835 100644
--- a/fpdfsdk/include/pdfwindow/PWL_Wnd.h
+++ b/fpdfsdk/include/pdfwindow/PWL_Wnd.h
@@ -284,7 +284,7 @@ class CPWL_Wnd : public CPWL_TimerHandler {
 
  public:
   CPWL_Wnd();
-  virtual ~CPWL_Wnd();
+  ~CPWL_Wnd() override;
 
   void Create(const PWL_CREATEPARAM& cp);
   virtual CFX_ByteString GetClassName() const;
@@ -373,7 +373,6 @@ class CPWL_Wnd : public CPWL_TimerHandler {
 
   IFX_Edit_FontMap* GetFontMap() const;
   IPWL_Provider* GetProvider() const;
-  virtual IFX_SystemHandler* GetSystemHandler() const;
   IPWL_FocusHandler* GetFocusHandler() const;
 
   int32_t GetTransparency();
@@ -399,6 +398,9 @@ class CPWL_Wnd : public CPWL_TimerHandler {
   virtual void SetCursor();
 
  protected:
+  // CPWL_TimerHandler
+  IFX_SystemHandler* GetSystemHandler() const override;
+
   virtual void CreateChildWnd(const PWL_CREATEPARAM& cp);
   virtual void RePosChildWnd();
   void GetAppearanceStream(CFX_ByteTextBuf& sAppStream);